06 August 2007

The wave of the future

A study was published in JGR Atmospheres this week entitled “Doubled length of western European summer heat waves since 1880”. While I haven't read the paper, there have been several 'popular science'-type stories which give many of the salient details. For example (also, here and here):

The most accurate measures of European daily temperatures ever indicate that the length of heat waves on the continent has doubled and the frequency of extremely hot days has nearly tripled in the past century. The new data shows that many previous assessments of daily summer temperature change underestimated heat wave events in western Europe by approximately 30 percent.

From a science perspective, an important point is that these data have been homogenized, that is, they have had the artificial trends and discontinuities associated with observational practices, instrumentation changes and such identified and corrected, giving a more accurate estimate of the longer-term behaviour of the time series.

I would suspect that these findings reinforce the notion that the heat over SE Europe can be regarded as an impact of climate change. The map, from IRI at Columbia University, shows temperature anomalies over the past three months (May, June and July) over Europe. Anomalies of 2C are seen across much of southern Europe, from Italy to points east. Peak anomalies of over 3 C were observed in Romania.

The impacts have been enormous. Here are a few with representative links:

If we act now, reduce our emissions and move towards a sustainable lifestyle and economy, then this is our future. If not, things will likely get worse, with more heat waves, droughts, floods and fires. It's our choice.

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